KR20150038171A - Low temperature vibration damping pressure sensitive adhesives and constructions - Google Patents

Abstract

The present invention relates to viscoelastic damping materials and viscoelastic structures that can exhibit low temperature performance and adhesion and can be used to make vibration attenuating composites. The present viscoelastic damping materials and constructions may comprise polymers or copolymers of monomers according to formula (I)
CH ₂ = CHR ¹ -COOR ²
Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a low-temperature vibration attenuating pressure-

The present invention relates to viscoelastic damping materials and viscoelastic structures that can exhibit low temperature performance and adhesion and can be used to make vibration attenuating composites.

Briefly stated, the present invention provides a viscoelastic attenuating material comprising: a) at least one monomer according to formula I:

CH₂= CHR^One-COOR²  [I]

Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms, and ii) a copolymer of at least one second monomer; And b) at least one adhesion-enhancing material. In some embodiments, the adhesion-enhancing material is one of an inorganic nanoparticle, a core-shell rubber particle, a polybutene material, or a polyisobutene material. Typically, R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. Typically, R ¹ is H or CH _3. Typically, the second monomer is acrylic acid, methacrylic acid, ethacrylic acid, acrylic acid esters, methacrylic acid esters or ethacrylic acid ester esters. The present viscoelastic attenuating material may further comprise a plasticizer.

In another aspect, the present invention provides a viscoelastic attenuating material comprising i) at least one monomer according to formula I:

CH₂= CHR^One-COOR²  [I]

Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms, and ii) a monofunctional silicone (meth) acrylate oligomer, . Typically, R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. Typically, R ¹ is H or CH _3. The present viscoelastic attenuating material may further comprise a plasticizer.

In another aspect, the present invention provides a viscoelastic structure comprising: a) at least one viscoelastic layer comprising a polymer or copolymer of at least one monomer according to formula I:

CH₂= CHR^One-COOR²  [I]

Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms; And b) at least one PSA layer comprising a pressure sensitive adhesive, wherein a) at least one viscoelastic layer is bonded to said b) at least one PSA layer. In some embodiments, the viscoelastic layer is bonded to at least two layers comprising a pressure sensitive adhesive. Typically, R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. Typically, R ¹ is H or CH _3. In some embodiments, the viscoelastic layer comprises a copolymer that is a copolymer of at least one second monomer selected from acrylic acid, methacrylic acid, ethacrylic acid, acrylic acid esters, methacrylic acid esters, or ethacrylic acid esters. In some embodiments, the PSA layer comprises an acrylic pressure sensitive adhesive. In some embodiments, the PSA layer comprises an acrylic pressure sensitive adhesive that is a copolymer of acrylic acid.

In another aspect, the present invention provides a viscoelastic structure comprising: a) discrete particles of a polymer or copolymer of at least one monomer according to Formula I:

CH₂= CHR^One-COOR²  [I]

Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms; And b) a PSA layer comprising a pressure sensitive adhesive, wherein a) the discrete particles are dispersed in b) the PSA layer. In some embodiments, the PSA layer comprises an acrylic pressure sensitive adhesive. In some embodiments, the PSA layer comprises an acrylic pressure sensitive adhesive that is a copolymer of acrylic acid.

In another aspect, the present invention provides a vibration attenuating composite comprising a viscoelastic attenuating material or a vibration attenuating composite of the present invention bonded to at least one substrate. In some embodiments, the material or structure is bonded to at least two substrates. In some embodiments, at least one substrate is a metal substrate.

The present invention provides material sets and constructions exhibiting pressure sensitive adhesives (PSA) that provide both substantial adhesive performance and durability when used with various substrates over a wide temperature range as well as vibration attenuation performance at cryogenic and high frequencies. The combination of low temperature attenuation and adhesion performance obtained using a single material set or structure presents a significant technical challenge in the field of viscoelastic damping materials. In some embodiments of the present invention, this is accomplished through the use of a special acrylic material, a specific additive, a multilayered structure, or a combination of the foregoing.

The present invention provides material sets and structures that exhibit pressure sensitive adhesives that provide both substantial adhesive performance and durability when used with various substrates over a wide temperature range as well as vibration attenuation performance at cryogenic and high frequencies. In some embodiments, the material or structure according to the present invention exhibits a high tangent delta as measured by Dynamic Mechanical Analysis (DMA) at -55 占 폚 and 10 Hz as described in the following examples. In some embodiments, the material or structure according to the present invention has a thickness of greater than 0.5 (as measured by Dynamic Mechanical Analysis (DMA) at -55 캜 and 10 ㎐, as described in the Examples below) But in some embodiments greater than 0.8, in some embodiments greater than 1.0, in some embodiments greater than 1.2, and in some embodiments greater than 1.4 tangent deltas. In some embodiments, the material or structure according to the present invention exhibits a high peel adhesion when measured as described in the Examples below. In some embodiments, the material or structure in accordance with the present invention is greater than 10 N / dm 2 (in some embodiments, greater than 20 N / dm 2, in some embodiments greater than 30 N / dm, in some embodiments greater than 40 N / dm, in some embodiments greater than 50 N / dm, and in some embodiments greater than 60 N / dm. In some embodiments, a material or structure in accordance with the present invention simultaneously achieves high tangent deltas at one or more of the aforementioned levels and high peel forces at one or more of the aforementioned levels.

In some embodiments, the viscoelastic attenuating material according to the present invention comprises a long chain alkyl acrylate copolymer which is a copolymer of monomers comprising one or more long chain alkyl acrylate monomers. Long chain alkyl acrylate monomers are typically acrylic acid esters, methacrylic acid esters or ethacrylic acid esters, but typically acrylic acid esters. In some embodiments, the side chains of the long chain alkyl have from 12 to 32 carbon atoms (C12 to C32), in some embodiments at least 15 carbon atoms, in some embodiments at least 16 carbon atoms, and in some embodiments up to 22 Carbon atoms, in some embodiments up to 20 carbon atoms, in some embodiments up to 18 carbon atoms, and in some embodiments, from 16 to 18 carbon atoms. Typically, the long chain alkyl has at least one branch point to limit the crystallinity in the polymer formed, which can inhibit damping performance. Long chain alkyl acrylates having no branch point can be used at a concentration low enough to limit the crystallinity of the polymer formed at the application temperature. In some embodiments, the additional comonomer is selected from acrylic acid, methacrylic acid, or ethacrylic acid, but typically is acrylic acid. In some embodiments, the additional comonomer is selected from acrylic acid esters, methacrylic acid esters or ethacrylic acid esters, but is typically an acrylic acid ester.

In some embodiments, the long chain alkyl acrylate copolymer comprises additional comonomers or additives that are bonded in the polymerization reaction and confer adhesive properties. Such comonomers may include polyethylene glycol diacrylate.

In some embodiments, the long chain alkyl acrylate copolymers can be combined in a polymerization reaction to provide a further void that can aid in imparting greater adhesion properties through control of the rheological properties of the viscoelastic damping copolymer, Monomers or additives. Such comonomers may include (meth) acrylic acid, hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, monofunctional silicone (meth) acrylate, and isobornyl But is not limited to.

In some embodiments, the viscoelastic damping copolymer can be crosslinked to improve the durability and adhesion properties of the material. Such cross-linking agents may include, but are not limited to, photoactivatable crosslinking agents such as benzophenone, or 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -triazine. The crosslinking agent may also include a copolymerizable polyfunctional acrylate such as polyethylene glycol diacrylate or hexane diol diacrylate.

In some embodiments, the viscoelastic damping copolymer may be polymerized through any known polymerization process, including thermal activation or photoinitiated polymerization. Such photopolymerization processes may include, for example, conventional photoinitiators such as diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide.

In some embodiments, the viscoelastic attenuating material according to the present invention comprises a long chain alkyl acrylate copolymer and an additional adhesion-enhancing material that imparts adhesive properties. Such additional adhesion-enhancing materials may include polybutene, silicone, or polyisobutene. Such additional adhesion-enhancing material may also be a particulate material. Such particulate adhesion-enhancing materials may include dry silica, core-shell rubber particles, or isostearyl acrylate microspheres.

In some embodiments, the long chain alkyl acrylate copolymers according to the present invention form part of a multilayer viscoelastic structure. In some embodiments, the long chain alkyl acrylate copolymers according to the present invention form a viscoelastic damping layer of a two-layer viscoelastic structure, wherein the second adherent layer is a layer of more highly adherent material over a wider temperature range. In some embodiments, the long chain alkyl acrylate copolymers according to the present invention form a viscoelastic damped core layer of a multi-layer viscoelastic structure sandwiched between two layers of a more highly adherent material. In some embodiments, the long chain alkyl acrylate copolymers according to the present invention form a layer of a multilayer viscoelastic structure that further comprises at least one layer of a more highly adherent material. In some embodiments, the long chain alkyl acrylate copolymers according to the present invention form an inner layer of a multi-layer viscoelastic structure further comprising at least two layers of a more highly adherent material. In some embodiments, the more highly adherent material is an acrylic PSA material.

In some embodiments, the two-layer viscoelastic structure includes a viscoelastic layer attached to a second layer that is a layer of a more highly adherent material. In some embodiments, a two-layer viscoelastic structure is made by laminating a viscoelastic layer to an adhesive layer. In some embodiments, the two-layer viscoelastic structure is made by applying an adhesive tape to the viscoelastic layer. In some embodiments, the two-layer viscoelastic structure is made by applying a liquid or aerosolized type of adhesive to the viscoelastic damping layer to provide greater adhesion to the damping layer. In some embodiments, the two-layer viscoelastic structure is made by applying a paste-type adhesive to the viscoelastic layer. In some embodiments, the two-layer viscoelastic structure is provided in the form of a roll, a sheet, or a pre-cut article. In some embodiments, a two-layer viscoelastic structure is fabricated just prior to use by applying an adhesive to the viscoelastic layer. In some embodiments, the two-layer viscoelastic structure is made in situ by applying the adhesive to the substrate and then applying the viscoelastic layer to the adhesive.

In some embodiments, the multilayer viscoelastic structure comprises a viscoelastic layer interposed between two layers of a more highly adherent material. In some embodiments, the multilayer viscoelastic structure is made by laminating a viscoelastic layer to at least one adhesive layer. In some embodiments, the multilayer viscoelastic structure is made by applying an adhesive tape to at least one side of the viscoelastic layer. In some embodiments, the multilayer viscoelastic structure is made by applying a liquid type adhesive to at least one side of the viscoelastic layer. In some embodiments, the multilayer viscoelastic structure is made by applying a paste-type adhesive to at least one side of the viscoelastic layer. In some embodiments, the multilayer viscoelastic structure is provided in the form of a roll, sheet, or pre-cut article. In some embodiments, the multilayer viscoelastic structure is fabricated just prior to use by applying the adhesive to the viscoelastic layer. In some embodiments, the multilayer viscoelastic structure is manufactured in situ by applying an adhesive to the substrate, applying a viscoelastic layer to the adhesive, and then applying an additional adhesive or an additional adhesive-containing substrate to the viscoelastic layer. In some embodiments, the multilayered structure is manufactured in situ by applying a viscoelastic damping composition in liquid form between two adhesive layers, and then curing the damping layer to form a viscoelastic damped copolymer.

The material or structure according to the present invention may be useful in aerospace applications requiring maximum attenuation performance of high frequency vibration energy at cryogenic temperatures in combination with good adhesion properties.

The objects and advantages of the present invention are further illustrated by the following examples, but the specific materials and amounts thereof recited in these examples, as well as other conditions or details, should not be construed as unduly limiting the present invention.

[Example]

Unless otherwise stated, all reagents are available from or available from Sigma-Aldrich Company, St. Louis, Mo., or can be synthesized by known processes. Unless otherwise reported, all ratios are by weight.

An example is described using the following abbreviations:

℉: Fahrenheit temperature

℃: Celsius temperature

cm: centimeters

g / ㎤: grams per cubic centimeter

Kg: kilogram

Kg / ㎥: kilograms per cubic meter

mil: 10 ^-3 inches

mJ / cm2: millimeter per square centimeter

ml: milliliter

mm: millimeter

μm: micrometer

N / dm: Newton per decimeter

pcf: pounds per cubic foot

pph: part per hundred

Test Methods

Peel adhesion test (PAT)

The force required to peel the test material from the substrate at 180 degrees was measured according to ASTM D 3330 / D 3330M-04. Using a rubber roller, a primed 2 mil (50.8 mm) poly (2-ethylhexyl) polystyrene resin available from Mitsubishi Plastics, Inc. of Greer, South Carolina, USA under the trade designation "HOSTAPHAN 3SAB" The adhesive samples were manually laminated onto the ester film and left at 23 [deg.] C / 50% relative humidity for 24 hours. A 0.5 x 6 inch (1.27 x 12.7 cm) section was cut from the laminated film and extruded at 0.10 inch (2.54 mm), obtained from Aerotech Alloys, Inc., Temecula, Calif. ) Or 0.20 inch (5.08 mm) thick Shore A 70, 320 Kg / m3 polyether-polyurethane foam, or grade 2024 aluminum test coupon. The tape was then manually bonded onto the test coupons using a 2 Kg rubber roller and conditioned for 24 hours at 23 [deg.] C / 50% relative humidity. Subsequently, a tensile tester, model "SP-2000" obtained from Imass Inc of Accord, Mass., USA, was used to measure peel adhesion at a platen speed of 12 inches / minute (0.305 m / min) . Three tape samples were tested for the example or comparative example and the average value was recorded in N / dm. Also record the abbreviated failure mode as follows:

A: Clearly debonded adhesive tape from substrate

2B: The adhesive tape is peeled off from the carrier backing,

C: Cohesive failure in which the adhesive layer is broken and the material remains in both the backing and the substrate.

Dynamic Mechanical Analysis (DMA)

Dynamic mechanical analysis (DMA) was determined using a parallel plate flowmeter, Model "AR2000 ", obtained from TA Instruments, New Castle, Delaware, USA. Approximately 0.5 gram of the viscoelastic sample was centered between two 8 mm diameter aluminum parallel plates of the flow meter and was compressed until the edges of the sample were consistent with the edges of these plates. The temperature of these parallel plates and the flowmeter shaft was then raised to 40 DEG C and held for 5 minutes. These parallel plates were then vibrated at a frequency of 10 Hz and a constant strain of 0.4%, during which time the temperature was reduced to -80 ° C at a rate of 5 ° C / min. The storage modulus (G ') and the tan delta were then determined.

The glass transition temperature (Tg)

We plotted the ratio of tangent delta to temperature, that is, G "/ G '. Tg is taken as the temperature in the maximum tangent delta curve.

Damping Loss Factor (DLF)

Composite materials were prepared as follows for attenuation loss factors. The nominal phase 6 x 48 in x 7 mil (15.24 x 121.92 cm x 0.178 mm) strip of aluminum was cleaned with a 50% aqueous solution of isopropyl alcohol and wiped dry. (LORD) 7701, available from Lord Corporation, Carrie, North Carolina, USA, with 20 pcf (0.32 g / cm 3) white microporous microcellular high density polyurethane The nominal phase of the foam was applied to a 6 x 48 x 0.1 inch (15.24 x 121.92 cm x 2.54 mm) strip. An adhesive tape was applied to this aluminum strip and nipped together to ensure complete wetting, followed by application to the primed surface of the high density urethane. A 5 mil (127 mm) adhesive transfer tape, available from 3M Company, St. Paul, Minn., Under the trade designation "VHB 9469PC" was then applied on the opposite side of the urethane strip. The resulting composite material was cut into 2 x 24 inch (5.08 x 60.96 cm) samples and applied to a 3 x 40 inch x 0.062 mill (7.62 x 101.4 cm x 1.58 mm) aluminum beam.

)로부터 전자기 진탕기 모델 "V203"에 기계적으로 결합하였다. 인라인 힘 변환기에 대해 빔의 반대측 상에, 또한 피에조트로닉스, 인코포레이티드로부터의 것인 가속도계, 모델 "353B16 ICP"를 장착하였다. 광대역 신호를 전자기 진탕기로 보내고, 빔 상에서 발췌된 진탕기의 힘을 측정하였는데, 이는 결과적으로 생긴 빔의 가속과 같다. 주파수 응답 함수(frequency response function, FRF)를 측정된 가속 및 힘의 교차 스펙트럼(cross spectrum)으로부터 계산하였으며, FRF의 크기로부터, 피크 진폭을 사용하여 모드 주파수를 확인하였다. 또한, 각각의 모드 주파수 주위의 반전력 대역폭(half power bandwidth)을, 모드 주파수 위와 아래로 -3 dB 진폭점들 사이의 주파수들의 스팬(span)으로서 확인하였다. 모드 주파수에 대한 반전력 대역폭의 비를 계산하고 감쇠 손실 인자로서 기록하였다.This beam was suspended by its first nodal points and the center of the beam was irradiated at a temperature of -10 DEG C, -20 DEG C and -30 DEG C in a thermally controlled chamber, Inline force transducer from PCB Piezotronics, Inc., Model "208M63 ", Brüel & Keith North America, Inc. of Norcross,

) To the electromagnetic shaker model "V203 ". On the opposite side of the beam to the inline force transducer was also mounted an accelerometer, Model "353B16 ICP ", from Piezotronix, The broadband signal was sent to an electromagnetic shaker and the force of the shaker extracted from the beam was measured, which is the same as the acceleration of the resulting beam. The frequency response function (FRF) was calculated from the cross spectrum of the measured acceleration and force. From the magnitude of the FRF, the peak frequency was used to determine the mode frequency. In addition, the half power bandwidth around each mode frequency was identified as the span of frequencies between the -3 dB amplitude points above and below the mode frequency. The ratio of the half power bandwidth to the mode frequency was calculated and recorded as the damping loss factor.

material

Abbreviations for the reagents used in the examples are as follows:

A-75: benzoyl peroxide, available from Arkema, Inc. of Philadelphia, Pa., Under the trade designation "LUPEROX A75 ".

AA: Acrylic acid obtained from Sigma-Aldrich Company, St. Louis, Missouri, USA.

BDDA: 1,4-butanediol diacrylate available under the trade designation "SR213 " from Sartomer, USA, LLC of Sartomer, Exton, Pennsylvania, USA.

DMAEMA: N, N-dimethylaminoethyl methacrylate obtained from the Sigma-Aldrich Company.

E-920: A methacrylate-butadiene-styrene copolymer available from Archaeema, King of Prussia, Pennsylvania under the trade designation "CLEARSTRENGTH E-920".

F-85E: Ester of hydrogenated rosin available from Eastman Chemical Company, Kingsport, Tenn., USA under the trade designation "FORAL 85-E ".

HDDA: 1,6-hexane diol diacrylate available from Satoromer, USA, EL, under the trade designation "SR238B ".

I-651: 2,2-dimethoxy-1,2-diphenylethane-1-one obtained from BASF Schweiz AG, Basel, Switzerland under the trade designation IRGACURE 651 .

IOA: Isooctyl acrylate, available from Satoromer, USA, EL, under the trade designation "SR440 ".

IOTMS: isooctyltrimethoxysilane obtained from Gelest, Inc., Morristville, Pa. USA.

ISF-16: 2-hexyldecanol available under the trade designation "ISOFOL 16 " from Sasol North America, Inc., Houston, Tex.

ISF-18: 2-hexyldodecanol, available from Sasol North America, Inc. under the trade designation "Isopall 18 ".

ISF-24: 2-decyltetradecanol available under the trade designation "Isopar 24" from Sasol North America, Inc.

KB-1: 2,2-dimethoxy-1,2-dimethoxyquinazoline, available from Lamberti USA, Inc. under the trade designation " ESACURE KB1 ", from Konsthorod- Di (phenyl) ethanone.

L-26M50: 50% solution of tert-butyl peroxy-2-ethylhexanoate in mineral spirits, available from Arkema Inc. under the trade designation "Luperox 26M50 ".

MTMS: methyltrimethoxysilane available from Gelest, Inc.

N2326: a 16.4% colloidal silica dispersion, available under the trade designation "NALCO 2326" from Nalco Company, Naperville, Illinois, USA.

PB-100: Polyisobutene having a molecular weight of 250,000, obtained from BASF Corporation, Freeport, Tex., Under the trade name "OPPANOL B-100 ".

PB-910: Polybutene having a molecular weight of 910, obtained from Ineos Oligomers, League City, Texas under the trade designation "INDOPOL H-100".

PB-1000: Polyisobutene having a molecular weight of 1,000, available from BASF Corporation under the trade designation "GLISSOPAL R-1000 ".

PB-1900: polybutene having a molecular weight of 2,500, available from BASF Corporation under the trade designation "Indian Pol H-1900 ".

PEGDA: Polyethylene glycol (600) diacrylate available from Satoromer, USA, Elle under the trade designation "SR610 ".

R-100: Random butadiene-styrene copolymer available from Satoromer, USA, EL, under the trade designation "RICON 100 ".

R-972: Hydrophobic dry silica obtained from Evonik Degussa Corporation, Parsippany, NJ, under the trade designation "AEROSIL R-972".

RC-902: Radiation-curable silicone obtained from Ebonic Degussa Corporation under the trade designation "TEGO RC-902".

S-1001: Styrene ethylene propylene block copolymer obtained from Kuraray Co. Ltd, Tokyo, Japan under the trade designation "SEPTON 1001".

SAMV: Ammonium lauryl sulfate obtained from the Stepan Company of Northfield, Illinois, USA, under the trade designation "STEPANOL AMV ".

T-10: Transparent silicone release liner, available from Solutia, Inc. of St. Louis, Mo., under the trade designation "CLEARSIL T-10".

T-50: Transparent silicone release liner, available from Solutia, Inc. under the trade designation "Clear seal T-50 ".

T-145A: Silicone resin available under the trade designation "TOSPEARL 145A" from Momentive Performance Materials Holdings, LLC, Columbus, Ohio.

TMT: 2,4-Bis (trichloromethyl) -6- (4-methoxyphenyl) -triazine.

TPO: diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide available from BASF SHUWAIS AGE under the trade name "DAROCUR TPO ".

467-MP: 2 mil (50.8 mm) adhesive transfer tape with paper liner, obtained from 3M Company under the trade designation "ADHESIVE TRANSFER TAPE 467 MP ".

467-MPF: 2 mil (50.8 mm) adhesive transfer tape with a film liner available from 3M Company under the trade designation "Adhesive Transfer Tape 467 MPF ".

The non-marketed materials described in the examples were synthesized as follows:

HEDA: 2-hexa-1-decyl acrylate. 100 grams of 2-hexyl-1-decanol, 45.97 grams of triethylamine and 350 grams of methylene chloride were added to a 1 liter flask and cooled to 5 DEG C using an ice bath. 41.1 grams of acryloyl chloride was slowly added dropwise over 1 hour, during which time the mixture was mechanically stirred. After 10 h, the mixture was filtered and then concentrated at 25 < 0 > C under vacuum. The remaining resulting oil was diluted with ethyl acetate and washed with 1.0 molar hydrochloric acid followed by 1.0 molar sodium hydroxide solution and then with saturated sodium chloride solution. The organic layer was then concentrated at 25 < 0 > C under vacuum. The crude oil was mixed with an equal volume of hexane and passed through a column of neutral alumina to remove the colored impurities and then the alumina was eluted with hexane. The collected filtrate was concentrated under vacuum at 25 < 0 > C, resulting in a colorless oil of 2-hexa-1-decyl acrylate.

ISA: Isostearyl acrylate. 197.17 grams of ISF-18, 78.12 grams of triethylamine and 700 grams of methylene chloride were added to a 2 liter flask and cooled to 5 DEG C using an ice bath. 69.86 grams of acryloyl chloride was slowly added dropwise over 1 hour, during which time the mixture was mechanically stirred. After 10 h, the mixture was filtered and then concentrated at 25 < 0 > C under vacuum. The remaining resulting oil was diluted with ethyl acetate and washed with 1.0 molar hydrochloric acid followed by 1.0 molar sodium hydroxide solution and then with saturated sodium chloride solution. The organic layer was then concentrated at 25 < 0 > C under vacuum. The crude oil was mixed with an equal volume of hexane and passed through a column of neutral alumina to remove the colored impurities and then the alumina was eluted with hexane. The collected filtrate was concentrated under vacuum at 25 < 0 > C, resulting in a colorless oil of 100% isostearyl acrylate.

ISA-MS: Isostearyl acrylate microspheres. Mixture A was prepared by adding 180 grams of ISA, 0.58 grams of A-75 and 1.8 grams of BDDA to a 500 ml glass jar and mixing in a roller mill until dissolved. 420 grams of distilled water, 7.2 grams of SAMV, and 1.8 grams of BDDA were added to a 1 liter glass beaker and a high shear mixer from OCI Instruments, Waterbury, Conn., OMNI- -MIXER) "to make the mixture B homogeneous. Mixture A was then added to the glass beaker and high shear mixing was continued for about 2 minutes until very small droplets of about 3 micrometer in diameter were formed. The product was then transferred to a 1 liter glass reactor equipped with a mechanical stirrer. The reactor was charged with nitrogen gas, heated to 65 占 폚, maintained at this temperature with continued stirring for 24 hours, after which it was cooled to 23 占 폚. The resulting suspension was filtered through a cheese cloth to remove aggregates and coagulated with 500 ml of isopropanol. The coagulum was then dried in an oven at 45 DEG C for approximately 16 hours.

Single layer  structure

Sample 1

A 25-drums (92.4 mls) vial was filled with 19.6 grams of HEDA, 0.4 grams of AA and 0.008 grams of I-651. The monomer mixture was stirred at 21 占 폚 for 30 minutes and purged with nitrogen for 5 minutes and then poured into a vessel of a Fisher Scientific (Pittsburgh, Pa., USA) until a coatable pre-adhesive polymer syrup was formed. , "BLACK RAY XX-15BLB" An additional 0.032 grams of I-651 and 0.03 grams of PEGDA was polymerized using a high speed mixer, model "DAC 150 FV" from FlackTek, Inc., Lancelot, Blended into syrup. The polymer syrup was then coated between the silicone release liner T-10 and T-50 at a thickness of approximately 8 mils (203.2 m) and cured by UV-A light at 2,000 mJ / cm2.

Samples 2 to 6

The procedure generally described in Sample 1 was repeated according to the amount of acrylate monomers listed in Table 1. The physical properties of the resulting cured adhesive coating are listed in Table 2.

[Table 1]

[Table 2]

Sample 7

A 25-drums (92.4 mls) vial was filled with 19.6 grams of HEDA, 0.4 grams of AA and 0.008 grams of I-651. The monomer mixture was stirred at 21 占 폚 for 30 minutes, purged with nitrogen for 5 minutes, and exposed to low intensity ultraviolet light until a coatable pre-adhesive polymer syrup was formed. Additional 0.032 grams of I-651, 0.046 grams of PEGDA, and 2.0 grams of R-972 were sequentially blended into the polymer syrup using a high speed mixer. The polymer syrup was then coated between the silicone release liner to a thickness of approximately 8 mils (203.2 μm) and cured by UV-A light at 2000 mJ / cm 2.

Samples 8 to 33

The procedure described generally in Example 7 was repeated, wherein various amounts of dry silica, plasticizer, polybutene, polyisobutene, silicone, core-shell rubber particles and isostearyl acrylate microspheres were mixed with the amounts listed in Table 3 To blend into the pre-adhesive polymer syrup. The physical properties of the resulting cured adhesive coating are listed in Table 4.

[Table 3]

[Table 3] (Continued)

[Table 3] (Continued)

[Table 4]

Viscoelastic Core VEC-1

A 25-run (92.4 mls) vial was filled with 19.8 grams of HEDA, 0.2 grams of DMAEMA and 0.008 grams of I-651. The monomer mixture was stirred at 21 占 폚 for 30 minutes, purged with nitrogen for 5 minutes, and exposed to low intensity ultraviolet light until a coatable pre-adhesive polymer syrup was formed. An additional 0.032 grams of I-651 and 0.03 grams of TMT were sequentially blended into the polymer syrup using a high speed mixer. The polymer syrup was then coated between the silicone release liner T-10 and T-50 at a thickness of approximately 8 mils (203.2 m) and cured by UV-A light at 2,000 mJ / cm2.

Viscoelastic cores VEC-2 to VEC-10

The procedures generally described in VEC-1 were repeated according to the compositions listed in Table 5. For VEC-6, the nominal thickness was 16 mils (406.4 m). The physical properties of the viscoelastic core are listed in Table 6.

[Table 5]

[Table 6]

Multilayer structure

Adhesive Skin SKN-1

A 1 quart (946 mls) vial was filled with 372 grams of IOA, 28 grams of AA and 0.16 grams of I-651. The monomer mixture was stirred at 21 占 폚 for 30 minutes, purged with nitrogen for 5 minutes, and exposed to low intensity (0.3 mW / cm2) ultraviolet light until a coatable pre-adhesive polymer syrup was formed. An additional 0.64 grams of I-651 and 0.6 grams of TMT were sequentially blended into the polymer syrup using a high speed mixer. The polymer syrup was then coated between the silicone release liner T-10 and T-50 at a thickness of approximately 1 to 2 mils (25.4 to 50.8 mm) and cured by UV-A light at 1,500 mJ / cm2.

Adhesive skins SKN-2 to SKN-4

The procedures generally described in SKN-1 were repeated according to the monomer and tackifier compositions listed in Table 7. < tb > < TABLE >

[Table 7]

Sample 34

The adhesive skin SKN-1 was placed on a clean 12 x 48 x 0.5-inch (30.5 x 121.9 x 1.27 cm) glass plate and the upper silicone release liner was removed. One of the silicone release liners was removed from the sample of the viscoelastic core VEC-3 and the exposed surface of the core was placed on the exposed adhesive skin of SKN-1. The core and the skin were then laminated together by manually applying a hand roller over the release liner of the viscoelastic core. The release liner covering the viscoelastic core was removed, and the release liner of another sample of adhesive skin SKN-1 was similarly prepared. This skin was then laminated onto the core exposed by a hand roller to produce SKN-1: VEC-3: SKN-1 laminate. The laminate was then left at 50% RH and 70 ((21.1 캜) for 24 hours before testing.

Samples 35 to 42

The procedures generally described in sample 34 were repeated according to the adhesive skins and viscoelastic core structures listed in Table 8. For sample 42, the adhesive skin is indicated by the adhesive transfer tape 467-MP / 467-MPF. The physical properties of the resulting multi-layer structure are also shown in Table 8.

Sample 43

A 1 quart glass bottle was filled with 405 grams of ISA, 45 grams of IOA and 0.18 grams of I-651 - corresponding to composition "VEC-7 " The monomer mixture was stirred at 21 占 폚 for 30 minutes, purged with nitrogen for 5 minutes, and exposed to low intensity ultraviolet light until a coatable pre-adhesive polymer syrup was formed. An additional 0.72 grams of I-651 and 0.675 grams of TMT were sequentially blended into the polymer syrup using a high speed mixer. The polymer syrup was then coated between the layers of adhesive transfer tape 467-MP and 467-MPF to a thickness of approximately 8 mils (203.2 μm) and exposed by UV-A light exposure through the 467-MPF side at 2,000 mJ / And cured.

Samples 44 to 46

The procedures generally described in sample 43 were repeated according to the compositions for VEC-8, VEC-9 and VEC-10 listed in Table 5, respectively. The physical properties of the viscoelastic core and the resulting multilayer structure are listed in Tables 7 and 8, respectively.

[Table 8]

Attenuation performance

The DLF value was determined for the selected adhesive sample according to the test method described above. The results are listed in Table 9.

[Table 9]

It should be understood that various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and principles of this invention, and that the invention is not to be unduly limited to the illustrative embodiments set forth above.

Claims (28)

a) i) at least one monomer according to formula I:
CH ₂ = CHR ¹ -COOR ² [I]
Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms,
ii) a copolymer of at least one second monomer; And
b) a viscoelastic attenuating material comprising at least one adhesion-enhancing material. The viscoelastic damping material of claim 1, wherein the adhesion-enhancing material is selected from the group consisting of inorganic nanoparticles, core-shell rubber particles, polybutene material, and polyisobutene material. The viscoelastic damping material of claim 1, wherein the adhesion-enhancing material is a silica nanoparticle. The viscoelastic damping material of claim 1, wherein the adhesion-enhancing material is a core-shell rubber particle. 5. A viscoelastic damping material according to any one of claims 1 to 4, wherein R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. The method according to any one of claims 1 to 5, R ¹ is H or CH ₃ a, the viscoelastic damping material. 7. The composition according to any one of claims 1 to 6, wherein said at least one second monomer is selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, acrylic acid esters, methacrylic acid esters and ethacrylic acid esters , Viscoelastic damping material. i) at least one monomer according to formula I:
CH ₂ = CHR ¹ -COOR ² [I]
Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms, and
and ii) a monofunctional silicone (meth) acrylate oligomer. 9. A viscoelastic damping material according to claim 8, wherein R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. The method of claim 8 or 9, R ¹ is H or CH ₃ a, the viscoelastic damping material. 11. A viscoelastic damping material according to any one of claims 1 to 10, further comprising a plasticizer. a) at least one viscoelastic layer comprising a polymer or copolymer of at least one monomer according to formula I:
CH ₂ = CHR ¹ -COOR ² [I]
Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms; And
b) at least one PSA layer comprising a pressure sensitive adhesive, wherein a) at least one viscoelastic layer is bonded to said at least one PSA layer. 13. The viscoelastic structure of claim 12, wherein the viscoelastic layer is bonded to at least two layers comprising a pressure sensitive adhesive. 14. A viscoelastic structure according to claim 12 or 13, wherein R < ² > is a branched alkyl group containing from 15 to 22 carbon atoms. 14. The viscoelastic structure according to claim 12 or 13, wherein R < ² > is a branched alkyl group containing from 16 to 20 carbon atoms. Of claim 12 to claim 15 according to any one of items, R ¹ is H or CH ₃ a, the viscoelastic structure. The viscoelastic layer according to any one of claims 12 to 16, wherein the viscoelastic layer comprises at least one member selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, acrylic acid ester, methacrylic acid ester and ethacrylic acid ester Lt; RTI ID = 0.0 > a < / RTI > second monomer. 18. A viscoelastic structure according to any one of claims 12 to 17, wherein the PSA layer comprises an acrylic pressure sensitive adhesive. 19. The viscoelastic structure according to claim 18, wherein the acrylic pressure-sensitive adhesive is a copolymer of acrylic acid. a) discrete particles of a polymer or copolymer of at least one monomer according to formula I:
CH ₂ = CHR ¹ -COOR ² [I]
Wherein R ¹ is H, CH ₃ or CH ₂ CH ₃ and R ² is a branched alkyl group containing from 12 to 32 carbon atoms; And
b) a PSA layer comprising a pressure sensitive adhesive, wherein a) the discrete particles are dispersed in the b) PSA layer. 21. The viscoelastic structure of claim 20, wherein the PSA layer comprises an acrylic pressure sensitive adhesive. 22. The viscoelastic structure according to claim 21, wherein the acrylic pressure-sensitive adhesive is a copolymer of acrylic acid. 11. A vibration attenuating composite comprising the viscoelastic attenuating material of any one of claims 1 to 11 adhered to at least one substrate. 24. The vibration damping composite of claim 23, wherein the viscoelastic attenuating material is bonded to at least two substrates. 25. A vibration damping composite according to claim 23 or 24, wherein at least one substrate is a metal substrate. 22. A vibration damping composite comprising the viscoelastic structure of any one of claims 12 to 22 bonded to at least one substrate. 27. The vibration damping composite of claim 26, wherein the multilayer viscoelastic structure is bonded to at least two substrates. 28. The vibration damping composite of claim 26 or 27, wherein the at least one substrate is a metal substrate.